Fix async gap handling. (dart-lang/stack_trace#84)

Fix an issue where an async gap at the end of a stack trace would not
get parsed correctly due to the trailing newline being `trim()`'d.

Add tests to cover this case.
4 files changed
tree: 3459a84bd1f88ab8f56ec6b9e96c0f9b56ef10bd
  1. pkgs/